Numerical Simulation Of Solid Particle Erosion And Wear In Oil And Gas Pipelines

With the rapid development of China's national economy,the demand for energy is increasing day by day.Oil and natural gas have become an indispensable and important energy in people's lives.As the main transportation way of oil and natural gas,pipeline plays an important role in the exploitation and transportation of oil and natural gas.In recent years,due to the increase in sand production during the development of oil and gas fields,the content of solid particles in gathering and transportation pipelines has also increased.The solid particles flow along with the fluid in the pipeline,constantly eroding and corroding the wall of the pipeline.In the long run,the pipeline will be thinned,and eventually the pipeline will fail.As a typical pipe fitting in the pipeline transportation system,the reducing pipe is easy to be eroded and worn.Therefore,the study on the flow field distribution and erosion rules of the twophase flow in the variable-diameter pipe can play a role in predicting the failure position of the pipeline in the actual production process,and it is of great significance to study the erosion of the pipeline in the actual working condition.This paper mainly takes the tapered tube as the research object,and explores its erosion and wear in gas-solid two-phase flow and liquid-solid twophase flow.The numerical simulation method was used to establish the model and condition of the erosion problem in the reducing pipeline,and the CFD software was used to simulate and calculate the flow field distribution and erosion distribution;The inlet velocity,particle size,and particle mass flow rate were studied separately to explore the influencing factors of erosion and wear,and to discuss the impact of different media on erosion.Meanwhile,the erosion of gas-solid and liquid-solid two-phase flow in the tapered pipe was analyzed and summarized.In addition,the calculation method and erosion results of the liquid-solid two-phase flow of the shrink tube are also analyzed by the same method.Finally,the erosion of the shrink tube and the reducer tube are compared and analyzed.The numerical simulation analysis of the gas-solid two-phase flow tapered pipe was carried out to obtain the erosion wear law of the tapered pipe,and the erosion wear of the tapered pipe under different media was compared and analyzed.The erosion is mainly concentrated on the throat of the tapered pipe and the shrink section 2D?3D away from the throat.When the inlet velocity is small,the increase of the velocity is not enough to affect the erosion and wear,and the erosion and wear rate is almost unchanged;when the inlet velocity increases,the erosion rate increases gradually.As the particle size increases,the erosion rate generally decreases.As the mass flow rate increases,the erosion rate continues to increase,and the erosion situation becomes more serious.When the inlet velocity is 15 m/s,the erosion rate is minimum.When the transport medium is a mixture of air and sand,the law of erosion and wear is basically consistent with that of natural gas containing sand,and the erosion rate is obviously higher than that of natural gas with sand,and the erosion behavior is stronger.The numerical simulation analysis of the liquid-solid two-phase flow reducer was conducted to obtain the erosion wear of the reducer,and the erosion wear law of the reducer under different media was compared.The erosion of the tapered tube is mainly concentrated at the outlet of the throat and the shrink section.The erosion rate changes with various factors.After exploring the sandcontaining heavy oil,the erosion of the pipe wall by the particles in the heavy oil under the same flow state was obtained.Through comparative analysis,it is concluded that the erosion rate of sand-bearing heavy oil is lower than that of sand-bearing crude oil,and the erosion behavior is weaker.In addition,the numerical simulation analysis of the liquid-solid two-phase flow shrinkage tube shows that the erosion wear is mainly concentrated in the pipe shrinkage,and the lower wall surface of the pipe shrinkage is the most severe erosion wear area.The erosion rate and erosion behavior increase with the increase of inlet velocity and particle mass flow rate,but decrease with the increase of particle size.Through comparative analysis,it is found that in the liquid-solid twophase flow,the erosion wear of the tapered tube is better than that of the shrink tube.